Metal coating.



E. W. McMULLEN.

METAL'COATING.

.APPLICATION FILED FEB. 1|, 1918.

1 ,26,97@ Patented J 11110 11, 1918.

AA COOK/P UNITED STATES PATENT OFFICE.

EABLE W. MOMULLEN, 0F KENOSHA, WISCONSIN, ASSIGNOR T0 SIMMONS COMPANY,OF KENOSHA, WISCONSIN, A CORPORATION OF DELAWARE.

METAL COATING.

Specification of Letters Patent.

Patented June 11, 1918.

Application filed February 11, 1918. Serial No. 216,581.

and State of Wisconsin, have invented cer tain new and usefulImprovements in Metal Coatings, of which the following is aspecification.

My invention relates to improvements in metal coatings and hasparticular reference to an ornamental finish for steel or other ferrousmetal.

The object of the invention is to provide for steel articles apractically indestructible coating, or finish, which shall possesssanitary and ornamental properties and characterlstics to a high degree,while at the same time having great durability and mechanical strengthand the maximum adhesive effect.

My invention briefl involves the covering of steel or other errous metalwith an electrolytic deposit of zinc and subsequently applying, bysprayin or otherwise, to the top of said coating a 'shing coat of toughlacquer or analogous materia The drawing shows a piece of ferrous metalcoated according to my'process.

During recent years liquid finishes, generally known in the trade aslacquers have been developed and utilized to a considerable extent forthe purpose of coating metal articles and with considerable success insofar as they may have been used upon nonferrous or non-oxidizablemetals such as brass, copper and the like. However, so far as I aminformed, no practical lacquer has, up to the present, been successfullydel veloped for use directly upon the outer surface of an article whichwhen in the proper tion, does not furnish a foundation to which lacquerwill stick with an degree of certainty. Also it has been ound that whenlacquer is applied directly to a steel surface it does not adequatelyprotect the steel against rust due to the oxidizing effect of theatmosphere. I

I have discovered that certain grades of lacquer and particularly thatkind of lacquer which has a cellulose or celluloid base can besuccessfully applied to steel, if the latter be first coatedelectrically with a non-ferrous metal such as zinc. 'This discovery,

me after numerous attempts to was made by first coating metal secure thesame result by 'rying out my invention.

made of a ferrous metal finished condiparts with the zinc by means ofthe hot process, that is to say by dippin the article into a bath ofmolten zinc. These attempts of mine to lacquer hot galvanized steelparts were, however, uniformly unsuccessful for the reason, I believe,in the light of my present knowledge, that a hot galvanized coating istoo smooth to provide the necessary adhesive effect. On the other hand Ihave discovered that the surface of a steel article to which there hasbeen applied an electrolytic deposit of zinc furnishes an admirablefoundation for the lacquer for the reason that the surface of saiddeposit when examined under a microscope is found to be of a uniformcrystalline texture to which the lacquer adheres with the reatesttenacitAlthough it is possible that other types of lacquer may be employed inpractising my invention, I prefer to use a lacquer of the cellulosegroup, a. a, a lacquer derived from cellulose. The one with which I havesecured the best results is the celluloid lacquer.

No special apparatus is required for car- As successfully carried outthe steel article to be coated is galvanized electrically by the coldprocess in the same manner as any ordinary electroplating process, afterwhich the article is washed and dried in the usual manner and when dryis sprayed with the lacquer by means of a suitable air brush. When drythe lacquer coating is strongly'adherent to the surface of the metal andwill not flake off or crack even though the surface of the metal be veryseriously disfigured or otherwise distorted out of its original shape.This feature is of inestimable value in the case of metal bedsteads orother furniture constructed of relatively thin steel sheets or tubingsuch as is now rapidly becoming the best modern practice in metalfurniture construction.

My improved 0 advantage that in ating has the additional the event thesurface of the lacquer is accidentally removed by abrasion, orotherwise, the surface of the steel does not oxidize and rust because itis protected by the zinc coating beneath the lacquer.

It should be understood that my invention is not confined to transparentlacquer but may be used for producing all kinds of lac- @3 answer querfinish according to present day lacing of zinc upon the said surface andsubquering practice. sequently coating the deposit with a cellu- I claimlose lacquer. 15

1. The improvement in the art of coating 3. As a new article ofmanufacture, a 5 steel or other ferrous metal which consists lacqueredferrous article provided with an in electrolytically depositing acoating of intermediate electrolytic zinc deposit under zinc upon thesurface of the metal and subthe lacquer coating. sequently covering thesaid deposit with 4. Asa new article of manufacture, a steel 20 lacquer.part coated electrolytically with zinc de- 10 2. The improvement in theart of beautiosit, and having an outer coat of cellulose fying andprotectinv a steel surface which acquer covering said deposit. conslstsin electrolytically depositing a coat- JEARLE McMULLEN.

